Loading machine



May 1 8, 1948. J. B. McDAm-z LOADING MACHINE Original Filed Aug. 8, 19458 SheetsfSheej; 1

J. B. MCDADE LOADING MACHINE May ,18, 1948.

8 Sheet-Sheet 2 Original Filed Aug. 8, 1945 May 18, 1948. J, B, McDADELOADING MACHINE original Filed Aug. 8.. 1945 l a sheets-sheet s J. B.MCDADE LOADING momma* May 1.8, 1948.

original Filed Aug. 8, 194s 8 sheds-sheet 4' alu-uli f SQ @N MMNN May1s, 194s. I l J, B, Mc-DADE 2,441,582

LOADING MACHINE original Filed Aug. a, 1945 s sheets-sheet 5 Tw/w50?" Jm.E

J. B. Mc'DADE LOADING MACHINE May 18, 1948.

Original Filed Aug. 8', 1945 8 Sheets-Sheet 6 J. B. MCDADE LOADINGMACHINE May 18, 1948.

Original Filed Aug. 8, 194.5v I 8 Sheets-Sheet 7 May 18, 1948. J. B.McDAD LOADING MACH'INE Original Filed Aug. 8, 1945 8 Sheets-Sheet 8-Patented i May 18, 1948 Original application August 8, 1945, Serial No.

609,551. Divided and this application November 14, 1945, Serial No.628,592

14 Claims. (Cl. 214-137) My invention relates other material.

The present application is a division of my copending application,Serial No. 609,551, filed August 8, 1945, and is directed to a speciesnotv retained in the parent application.

The main functional purpose of my invention is to provide a coal loadingmachine suited to use .where the passageway in which the loader'operatesis low and the space between supports within which the loading head mustwithdraw for bucket discharge is narrow vor is constrlcted by theposition and relation of the supports.

A further purpose is to provide a coal loader in which the insertion ofthe empty loader shovel and the withdrawal of the loaded shovel do notrequire overhead support or in which the support can be maintained veryclose to the ground.

A further purpose is to provide a loading head which can be engagedwith-the cut pile of coal bydirect thrust and in which continued thrustcarries the shovel forwardly through the pile of coal and upwardly to lland lock the shovel in upward filled position ready for withdrawal.

A further purpose is to project a scoop or shovel from a positionoutside a narrow vein of coal into a pile of coal to be loaded and atthe same stroke, by the equivalent of a hammer blow, to push the scoopthrough the pile 'and turn it to an upright, lled position.

A further purpose is to project the scoop in a direct line into the pileof coal which is to be loaded, turn it up, withdraw it in a straightline to a convenient point and project it in a different direction fordischarge, whereby the limited space available between pillars and otherencumbrances may be used to the best advantage anda machine of fullcapacity can be projected and withdrawn to the best advantage.

In a vertically tiltable loader having a shovel head, a further purposeis to balance the weight of the shovel and the plunger mechanism infront of a tilting axis at their reducing leverages during withdrawalagainst the weight of the plunger in the rear of this axis at theplungers increasing leverage so that a point is 'reached in withdrawalof the shovel where the weight and leverage in front of the axis areoverbalanced bythe weight and leverage of the plunger behind the tiltingaxis, and the loaded shovel is lifted from the floor so that it may beswung horizontally and projected to discharge.

A further purpose is to provide a shovel head carrying a rack andmounted on side rods, to project the head forward to any pre-setadjustto a loader for coal or 'able position 'by an hydraulic ram, tomove the shovel forward beyond the movement of the head and to rotatethe shovel to a illledposition by continued movement of the ram afterthe rack has ceased to move.

A further purpose is to swing a shovel-carrying operating mechanismabout a horizontal center while projecting the shovel into the coal tobe loaded, in using a rack which is restricted to straight line motionand a pinion which is rigid with the shovel to turn the shovel upwardlythrough the coal at the end of the forward strolre of theshovel and as apart of said forward movement, giving an hydraulic blow to the shoveltolift it into illled position, and subsequently retracting theshovel-operating mechanism and the shovel from the loading position.

A further purpose is to support a shovel from movement, and to revolveit at or beyond this` forward limit.

A further purpose is to support a shovel while hydraulically driving itforward to a point of intended use, to stop the forward movement at thepoint of use and then vertically to tilt the shovel up through a pile ofmaterial to be gathered.

A further purpose is to support a shovel or scoop upon rods lto anadjustable limit of forward position, to drive the shovel forward andinto the coal by an hydraulic ram generally limited in its forwardmovement by the adjustable means, to gear the shovel to a racktravelling with the shovel to its adjustable initial limit, and to turnthe shovel upwardly to complete the filling of the shovel by additionalmovement of the shovel and therefore of the gear after the rack hasceased to move forward.

A further purpose is, in the rear position of the shovel, to have therear of the mechanism tilted downwardly with respect to its mainoperating position and to haveI the shovel lifted in order that when themechanism is nearly horizontal asin the main shovel operation, theheight of the center of gravity may be as high as possible is order toincrease the coal capacity of the shovel. In other words, the space forcoal between the gear rack and the oor should be as great as possible togive pay-load capacity."

A further purpose is to thrust a shovel forthe movement of the rackwherever it is theY intention to turn the shovel up through the pile oimaterial to be gathered.

A further purpose is to turn a shovel upwardly upon an axis within thebody of the shovel so that as fllled, part of the load will be in therear of the axis and the rest of it in front of the axis.

A further purpose is to gather the load by scoop action upon a shovelsurface of such slope that when the shovel is tilted reversely, the loadwill slide from the shovel.

A further purpose is to revolve a gathering shovel forwardly andupwardly through a pile to be removed, lifting the content to uprightposition, to store energy in a spring by the upward movement, to latchthe shovel in the raised position and to use the energy stored forkick-oil' purposes when the latch is released in order to bring theshovel to initial position.

A further purpose is to provide an hydraulically driven shovel with stopmechanism carrying a turning rack, adjustable means for determining thestopping points at which the rack may be made effective and a segmentgear carried by the shovel engaging with the rack to turn the shovel upthrough the pile of material loaded, if and when the rack is stopped inits forward movement.

A further purpose is to secure as large a coal capacity as possible forthe gathering and loading shovel.

Further purposes will appear in the specifications and in the claims.

I have preferred to illustrate my invention by a few only lof the formsin which it may appear, selecting forms which are practical and eiectiveand which at the same time well illustrate the invention. y

Figure 1 is atop plan view of the device of my invention.

Figure 2 is a side elevation, largely in longitudinal section upon line2-2 of Figure 1.

Figure 3 is a longitudinal section corresponding generally with line 3-3of Figure 2. The jack is partly broken away.

Figure 4 is a side elevation taken generally upon line 4-4 of Figure 2,and looking from the rear in the direction of the arrow toward theshovel.

Figure 5 is a side 'elevation of the shovel and its operating mechanismshowing the shovel but not the other structure in two positions.

v Figure 6 is a top plan view of the mechanism seen in Figure 5.

Figure 7 is a perspective view of the shovel alone, from the open front,omitting the shoes.

Figure 8 is a perspective view of the shovel of Figure 7 from the rear,but modified by omitting the stop 2811 Figure 9 is a perspective view ofthe shovel of Figure 7, looking into the boots.

Figure 10 is a top plan view similar to Figure 6 but showing furtherdetailed mechanism on the rear plate.

Figure 11 is an end elevation of the right hand end of Figure 6, themechanism in the distance being omitted and the lock being shown asengaging a ratchet.

Figure 12 is a fragmentary longitudinal section of a modied check rodshowing special latching notches.

In the drawings similar numerals indicate like parts.

Mining operations are many times rendered much more difficult by thefact that the vein of coal is so thin that the removal oi.' the coalleaves little room in which to work and from which to remove the coalwhich has been mined.

In thin seams, the diiilculty in getting mechanism within the chambersto gather and remove the lbroken coal has been so great in the past thatthe work has been done by hand, using a hand shovel and in many casesrequiring the miner to lie on his side while he is attempting to scoopout the coal from the chamber. This is not only expensive but is veryhard upon the men who do the work.

The present invention is intended to follow,

generally, the operation of a hand shovel which is inserted beneath thepile and is progressively turned forwardly and upwardly to a point abovethe pile from which point it is then withdrawn to be emptied, usuallybeing emptied at the rear or at the side with respect to the face fromwhich the content has been gathered.

The present invention is especially adapted to mine thin seams of coalto advantage and in the form illustrated gathers and loads in and fromchambers as low in height as twenty inches.

There are various systems of mining coal. One system which will be citedbecause it illustrates to advantage the present invention is as follows:

Let us assume that an area of coal having a seam or vein of twentyinches thickness is to be mined and the coal is to be loaded by a loadercapable of entering the seam. Haulageways to the seam will be driven atintervals as the need arises. These will follow the contour of the seamcutting the full depth of the seam. If the haulageways are toaccommodate mine cars in present practice they will be ve feet high andmine cars will be used exclusively in them.

As each haulageway goes on through the seam there will be coal fortwenty inches of its height and the rest will be rock. The haulagewayneed not be higher than the seam thickness because if the seam be twentyinches, for example, a, belt conveyor can be used the length of thehaulageway to haul out the coal which has been cut or broken and isdelivered to it from the chambers.

On a fifty foot spacing, if the chambers be as wide as thirty feet, withcross cuts at intervals providing for access of air to the working face,there will then be twenty feet of seam coal -left which providespillars, left in place until it is removed as the operation is withdrawnfrom a section.

The chamber is successively advanced lengthwise by blasting or otherwisebreaking down the coal on the face of the seam. The loader is held inposition by jack pressure against the roof of the chamber and gathersthe coal which has been thrown down, dumping it upon conveyors which aresuccessively extended along the side of the chamber and which dischargeinto the mining cars or haulageway conveyors for ultimate withdrawal.

In Figure 1 of the drawing, one of my loaders is shown in a chamber,with a conveyor of well known type along the side of the loader.

The loader comprises generally a base 40 adapted to rest on the floor 4lof a chamber 42, a jack '43 suitable vfor engaging the roof 44 of thechambei', a turntable 45 and a tilting assembly 46, carrying a gatheringarm in thc form of a thrustor or projector unit. The machine includes apower plant 41 for the operating parts, a front crosshead shovelassembly 48, a shovel 49 and stop mechanism 5B.

When the loader has been placed in the position from which it isintended to operate, it

v ported.

Because the door of the chamberbin which the loader is to operate isnecessarily uneven, it is desirable that the base 40 cover a large area.It is anchored in position by a Jack 43 welded to the base and whose-upper end terminates in a socket 52 within which rests a nut 53. Theinterior nut thread 54 engages the thread 55 of the hardened jack point56. The nut is rotated by a hand wheel 51 and the thread may be keptfrom rotating. in any way of the many known.

The turntable 45 supports the entire tilting assembly and is mounted torotate about the jack, for convenience considered as in horizontalplanes. The turntable, as seen in Figure 1, supports the gathering(vertically tilting) assembly on one side of the jack position and apower plant for the gathering assembly on the opposite side thereof, soplaced for convenience merely in balancing. vTheoperating mechanism forthe gathering assembly comprises a motor 58, a pump 59, tank 60 for thehydraulic fluid-considered here as oil, oil intake 6I for the pump,fluid control 62, connection 63 from the pump to the control inlet 64and outlet 65 from thev control to the hydraulic cylinder 66 and return61 from the control to the oil tank.

The hydraulic control mechanism is an operating valve merely fordistributing the fluid from the pump to and from the hydraulic cylinder.It and its solenoid control are well known in the art. The valve can beoperated alternatively by the solenoids 68, 69, through electricalswitches 10 located at any suitable point or can be operated locally byany suitable fluid connections from a hand lever 1 I In order toaccommodate tilting of the gathering assembly, the fluid connections-aremade flexible.

The turntable is not merely free to turn but is turned by an electricmotor 12 and suitable connections. The motor may be supported above orbelow the turntable as preferred but in the illustration is above thetable. Upon the motor shaft 13 is located a pulley 14 connected by belt1-5 with a pulley 16 below the turntable. The pulley 16 rotates shaft 11carrying worm 18 engaging with worm gear 19 upon shaft 80 supported fromthe turntable. The shaft 80 carries a gear 8| which meshes with a fixedcircular rack 82, so that the turntableis rotated with respect to itssupport. There are so many ways of rotating the turntable that this issuggested merely as one operative way of performing the function.

Tilting of the lgathering assembly Upon the turntable at any' pointsuitable to balance the power plant are located horizontal trunnions 83about which pin the gathering assembly is capable of tilting. Thistilting action is preferably left wholly to gravity. The movement of theworking parts forward and back throws the center of gravity to the frontor the rear, as the case may be, of a verticalline through the trunnions83 and causes the tilting. Except as it may be desirable to -control bya lock, the tilting about the pin will be dependent wholly upon shiftingof the center of gravity due to extension or retraction of the plungerand to the shovel projected and retracted by it.

The tilting assembly is free to tilt in counter- 6 yclockwise directionas viewed in Figure 2 at al! times when the moment of the weight anddistance to the left of the shaft is greater than the moment of theweight and distance to the right of this shaft in the figure. However,it is desirable for certain purposes to prevent the tilting assemblyfrom turning in clockwise direction in Figure 2 as soon as the moment ofweight and distance at the right exceeds the moment of weight anddistance at the left.

As an alternative for the above automatic method of tilting thegathering assembly, the tilting may be accomplished by many various andobvious mechanical means; for example an hydraulic jack such as thatused in dump trucks, etc. D

At opposite sides of the cylinder sliding, bearings Illo are providedfor supporting and guiding side rods I0 I, which slide freely throughthe bearings and which along with piston or plunger |05, are rigidlyattached at their front ends to a front supporting crosshead |06, shownas made up of front and back crosshead plates I U1, |08. and at the rearof the rods to a rear plate |09.

Means of attachment of theside rods and Iof the frontend of the plungerare shown and are necessary, but their character is wholly immaterial. f

Conveniently above the side rods is located a check rod Ilo, which issupported against lateral movement in the rear plate but is free `toslide through a bearing III, supported by the rear plate.

The check rod performs two main functions; it provides for stoppage ofthe operating assembly to proper position for loading the shovel from apile end, and at that position it supplies a rack by which the shovelcan be turned forwardly and upwardly through the pile. The rack II 2 islocated at the front end of the check rod and is f1 le to slidelengthwise with respect to the front crosshead. y It is supportedagainst movement upwardly in the illustration by a bearing laterdescribed. The rack may to advantage be supported also on the tooth sideof the rack by a bearing surface. A segment gear, to be described,supports the tooth side I I4 of the rack.

Movement is imparted by the check rod through the rack to a. gear IIS,referred to as a segment gear because a segmental part only of the gearneed be used.

As shown later, the shovel will normally be locked in raised positionpreventing the segment gear from rotating, with the result that thesegment geary and rack will move bodily together and the plunger, siderods and check rod will all y move together to the left in Figure 2.

A check finger II8 engages with stops which project into its line oftravel from the relatively xed support, for the purpose of stoppingmovement of a check rod at any of a number of predetermined positions inorder that a shovel may begin operation at a point selected as a stop.Where bulldozing is intended, the relationship is set so that the stopwill not be engaged.

The upward turning movement of the shovel is continuous with its forwardthrust and is so rapid that perhaps the shovel should be considered aswhirled. The effect is as of a hammer blow. When it has been whirled tofilled position, as elsewhere more fully discussed, it is necessa/rythat it be held' in an upturned position during the withdrawal of theshovel so that the attempt to withdraw does not reverse the whirling ofthe shovel and spill the contents.A For 'position of the 1 this reason alatch is required to hold the shovel in its uptumed position; and thislatch also must be capable of convenient release after it has beenemptied in order that the empty shovel may assume its proper horizontalposition for the beginning of a new cycle.

In the use of the word shovel it is intended to include a containercapable of gathering fromy a pile whether the container might be morenaturally referred to as a bucket or as a scoop, for example, or not,because the present invention is considered to be applicable generallyto all such types of containers having openings into which the materialis gathered as the shovel is pushed forwardly. It is the intentiontherefore to give the shovel a generic meaning. Moreover, my inventionis capable of being used as a bulldozer or even as a rake to serve thegathering purpose.

Whatever the type o shovel, it is the intention to secure it on what iseffectively a geai and to mount the whole unit about an axis in a pin orother support so that the gear will mesh with the rack and shift therack if the gear rotate without translation but to cause rotation of thegear and of the shovel if the gear travel lengthwise of the rack whilemeshing with it.

The shovel is front emptying; may be emptied at any point along itstravel; and may be positioned at the same point for a new cycle withoutgoing back to the retracted position to release the latch holding theshovel up in loaded position. It tilts about an axis. within the body ofthe shovel, as distinguished from tilting about an axis outside of theshovel and has a specially advantageous-form o latch.

The runners .241i are differently placed and are in the form of whatmight be described rather as shoes than as runners. The shoes are shownin Figures 5 and 6 only. For some uses, neither runners nor shoes willbe needed and both have been omitted from the remainder of the figures.

The shovel has unusually great capacity.

Because the shovel discharges from the front and it is desirable not totilt it reversely to an excessive extent, lthe -fiont wall 200 slopesdownwardly and inwardly to a considerable extent, as shown in Figure 5.

Since the positions of the shovel correspond to different extents ofprojection of the check rod I|0 at the rear end 20| in the tiltingassembly and because the check rod is accessible at this point,advantage `is taken of the opportunity to latch the shovel in restedposition by latchlng the check rod at its rear end exposure. This isshown in Figures 6, and 11 and will be described later.

However, With this character of latch and a iront emptying shovel, theshovel not only can be emptied at any point in the length of its travelbut can be swung to its initial counterclockwise position, as comparedwith Figure 5, ready to start a new cycle. In connection With thelatching construction of the check rod in Figure 12, the shovelfurthermore is capable of latchlng with partial lling movement only ofthe shovel because of the presence of tortional springs 202, also to bedescribed at a later point.

With the use of the tortional springs and the latchlng mechanismengaging a ratchet latching keeper, it will be possible to completelyempty the shovel whether the shovel be initially fully filled or butpartly filled. so that a new cycle may be started at any point ofretraction at which it is desired to empty the shovel.

The shovel tilts by progressive driving movement of the plunger about atilting axis by reentrantly contouring the rear ofthe shovel. In

the central part of its length a. recess 20| (Figure 7) is provided bywall 200. At opposite ends of the shovel, in line with the recesses,pockets 208 are located, not only giving additional capacity formaterial loaded but also placing part of the coal in these pockets inposition to partially counterbalance the coal in the upper front of theshovel. l

Within the recess and between the pockets, I locate the segment IISeffective as a gear and because of the difculty in mounting it upon apin, I pass a shaft 208 through the length of the shovel as a supportfor the gear. The gear engages a rack upon check rod IIO, which checkrod may be stopped by a check nger. The check finger or the selectorbars may be turned one with respect to the other about the check rodaxis so that selectively the check fingers may iind any preferred checkrod within their path of movement or the check rod may be so located asnot to meet any of the selector bars and therefore as not to stopmovement oi the rack and not to cause revolution of the shovel.

The last use, freeing the check nnger from selector bar engagement, willbe used for special purposes where Vloulldozlng or raking is intendedand a special tool is used, or where a shovel, if used, is not intendedto be revolved. The check rod H0, in order to secure additionalstrength, is made up of a composite rod comprising an outer tubing 209within which operates a longitudinally extending, Ire-enforcing rod ZIB(Figures 5 and 6). The finger IIb in this form is a bar 2i I (Figure 5)which is fastened in the re-enforcing rod and extends transverselythrough openings in the tube so that the edges of the bar arelongitudinally supported by the walls of these openings.

The check rod is intended to cooperate with a shoulder sleeve 2I2 whichsurrounds the check rod and Which is cut a'way so as to provideprogressively at different lengths along the check rod, shoulders 2I32I3', 2I32, etc., against which the check finger is adapted to engageselectively according to the length of travel of the check` rodintended, before the shovel reaches the position at which it is to beloaded.

Since the selector bar sleeve may be mounted about the tubing of thecomposite check rod, it can be turned freely about this tubing topresent different shoulders within the path of movement of the checkfinger lI I8, which check finger, therefore, need not be rotated.Furthermore, the selector bar sleeve can be turned to a point at whichthe check finger will not engage any shoulder, permitting travel of thecheck rod along slot 2M without stoppage and therefore without anyrelative lengthwise movement between the rack and the gear. The slot 2I4 may be cut all the way through 0r be cut far enough through only sothat there will be no stoppage of movement of the check iinger H8. Ifthe slot be cut all the way through, the tubing may be selected of suchsize as to tend to spring shut about the intermediate tubing between itand the interior rod, so as to permit the shouldered, outer tube to beretained in adjusted positions by the friction upon the intermediatetube. Advantage is taken of circumierential spring of a cut tube thesize of the outer tube carrying the shoulders which may be such that itwill just hug the intermediate tube with sufficient friction so as topermit longitudinal movement of the check rod through it to causeengagement of the check finger with the shoulders while having enoughfriction to prevent circumferential movement between the outer and theintermediate tubes. ,The shouldered selector tube may be rotated byhandle 2|! to secure new positions.

Another form of selector bar and check finger construction appears inFigure 12 where the check nger 2|8 is capable of being adjustedcircumferentially so as to cooperate in its longitudinal movement withselector shoulders of a type shown in Figure 5, but anchored againstcircumferential movement that is rigidly fixed to some suitable support.The form in Figure 1 2 has the great advantage that it can be suppliedwith a latch-like indicatonwhich will show the position of theparticular bar or shoulder, with which the selector finger is .intendedto cooperate. Because this adjustment to different selector barpositions must be made in a narrow space under cramped conditions, it isa great advantage to have the adjustment capable of being made at theextreme rear of the thrustor and to have the advantage of an indicatorat this extreme end by which the position of the check finger withrespect to the bars or shoulders can y be determined accurately. Afurther advantage in the form of Figure 12 lies in the fact that if themechanism is capable of being set by means located wholly at the rear ofthe thrustor, a large part of the remainder of the mechanism can beprotected by a covering 2|1 (Figure 5) with considerable advantage inprotection of the mechanism.

In Figure 12 the check rod H02 may be tubular but unaltered in contourfrom the rack back to if latching of the full stroke only of the shovelis to be provided. On the other hand, if it be intended to latch theshovel in whatever partly rotated position it may assume, this may beprovided byratcheted notches 23| (Figure 12) into any one of which thelatch 230 may iit, the movement of the selector rod pushing the ratchetfaces past the latch so that the latch will engage with that ratchetface farthest from the handle 228 reached by the rod as a result of theturning movement of the shovel and the reactive position of the gear inthis position of the shovel upon the rack and therefore upon the checkrod Aconnected with the rack. In this way, as the shovel turns inclockwise direction, as viewed in Figure 5, the latch'willbe pushed outsuccessively by the different ratchet faces shown from ratchet face 232to ratchet face 233; and the latch will rest in and hold at any of theintermediate locking faces 234.

One form of latch capable of use either with thesingle notch at 229 orwith the ratcheted notches at 23| is shown in Figures 10 and 11. In

a point close to the position of the check finger at which point all ofthe mechanism shown in Figure 12 can be located. The intention is toprovide a check finger 2li .which can be adjusted circumferentially andwhose adjustment can be indicatedat the rear of the mechanism where theadjusting means is also located.

In the construction shown', the ltubular check rod end is threaded at2|8 to receive a threaded stub 2|8 which should-preferably screw intothe thread of the tube tightly enough to remain in adjusted position.The stub 2I8 is rigid with a check finger body 220 which carries thecheck finger 2I6.

1f the stub 2 I9, therefore, be screwed 1n or out of the thread in themain part of the tube, the angular position of the check finger will bechanged correspondingly. It is necessary only, therefore, to providemeans by which the body 220 may be turned to screw the stub 2|9 rigidlyattached to it inwardly or outwardly to obtain the intended angularadjustment.

In the form shown, the body 220 isprovided with a threaded stub 22| onthe opposite side of the body from stub 2|9. This threaded stub 22|,rigid with the body, is extended at 222 in order to carry a lever arm223 which is held in pl-ace upon it as shown by a set screw 224. Thethreaded stub 22| and the extension in theform of shaft 222 issurrounded by a sleeve 225 which performs two functions. It is threadedupon the stub 22| to support rear ratchet recesses 226, within whichwill t a spring detent 221 carried by the adjusting handle 228, and thedetent face desirably car-ries any type of dial bywhich the angularposition may be determined fromthe end.

A further function of the sleeve 225 is that it is notched at 228 forengagement by a latch 230- not shown in Figure 12 but seen in Figure 11these figures, the actual latch which engags in the notch or notches islocated at one end of the lever 235, and is pivoted' at 236. It isspring pressed into engagement with the notch normally by a spring 23,1and is released from this notch when the current is on the solenoid bylink 238 which is the right hand link in Figure 10. When the solenoid isenergized, its armature 239 is drawn inwardly in the figure with theresult that lever 240 (Figure 10) is turned about its pivot 2.4i so asto pull the lever 238 outwardly in the direction of the arrow. The lever238 is pivotally connected at 242 with the latch 230 so that as the link238 is pulled outwardly in Figures 10 and l 11, the latch is releasedfrom the notch in which it may be engaged and is held in releasedposition as long as current is continued through the solenoidal winding.

In the shovels seen in Figures 5 and 6, the bottom of the shovel isprovided with shoes 243 and During the forward movement of the thrustor,the points 245 travel along the floor of the chamber and the frontsurface 246 lies substantially parallel with the floor of the chamber asseen in dotted lines in Figure 5.

During the retractive movement of the shovel While "the emptying of theshovel normally takes piace after at least partial retractive movementof the shovel, occasion arises also, of course, where the shovel is butpartially filled, and where it is desired to empty the content back onthe pile. Sometimes it will be desirable to discharge the content whenthe retractive movement is not great enough for the thrustor to tilt.

as a pendulum back beyond the point at which it would ultimately hang,and subsequently forward, repeating, until it stops. It thus movesfarther back than would be necessary for the content to slide down thefront wall and discharge. As later more fully explained, this pendulumaction is assisted by torque springs.

In the position shown in Figure it is not the intention that the points245 must actually engage the floor yof the chamber. Instead, they arepreferably slightly lifted so as to ride above the iioor, thus ridingover irregularities in kthe floor.

This lifting of the points does not interfere with the shovel properlydigging under and into the pile of material to be gathered.

It is desirable to keep the tilting assembly nearly horizontal for thereason that the long end with respect to the tilting axis, whether it bethe end at the rear or the shovel at the iront, must be limited in itsmovement to avoid striking the roof or the floor.

In Figure 5, the shovel shoes prOteCt against excessive elevation of therear of the tilting assembly. The tilting must evidently be controlledin both directions.

I have already described the locking of the tilting assembly in itsposition in'which the shovel is lifted on retraction, requiring that inprojected discharge position the shovel be lifted far enough from thefloor for there to be room for discharge of the content.

If the runners or shoes be omitted the shovel must be held in elevatedposition during retraction.

In the absence of shoes (Figures '1, 8, 9) the swinging of the shovelforwardly and upwardly, as in Figure 5, would mean that the bottom'ofthe shovel touches the floor of the chamber un less the tilting assemblyturn in counterclockwise direction about its anis.

If the Shoes be not used, it is desirable to maintain the shovel in thelifted position of Figure 5 during its entire retractive stroke in orderthat the shovel may not engage the floor, which would interfere with thehorizont-a1 swinging movement of the shovel to a new horizontal angularposition along which the shovel is to be projected to the point ofdischarge. In this structure, as in the earlier structures described,the tilting as sembly on retraction will tilt automatically to lift theshovel somewhat from the floor as soon as the center of gravity of theyassembly passes the tilting axis.

rIlhe shovel shown can have considerably greater capacity than those inwhich'the reentrant back is not used because the swinging of thesereentrant back shovels about an axis passing through part of the contentmakes it possible to gather the content into the shovels with much lesslifting effort than if the entire content be outside the axis.

Advantage is taken of this opportunity to enlarge the shovels byproviding lobes, pockets, booths or boots 252, 253, (Figure 8) in therear of the face 254 of the reentrant wall 255. These lobes compriseinner end reentrant walls 256, 251, bottom reentrant walls 258, and theouter end Walls 259, 260 of the shovel.

The supporting shaft passes through end walls 256, 251, 259, and 260,and is supported in bearings 26I, 262, welded to the walls 256, 251 inthe illustration.

shovel end. Releasing of It will be evident that the fact that theshovel content is tilted about an axis through the body of the shovelgreatly reduces the tilting effort required and permits the use of ashovel of greatly increased capacity, even though the capacity of thefront part of the center of the shovel is reduced by the reentrant wallswhich permit the gear to be inset as shown.

The slip bearing 263 in Figure 7 is fastened by plates 264 to the top ofside plates 265 whose lower portions are reinforced by collars 266 heldto the shaft 208 by set screws 262. The shaft is thus kept fromrotation.

The shaft is extended through as seen at the left hand end oi the figureat 269. Spiral springs 202' surround two ends of the shaft and are usedas torsional springs in order that the springs may be wound (tightened)during filling upward movement of the shovel, to latching position sothat the springs may be used to assist in the unloading reverse swingingmovement of the shovel when the latch at the back of the check rod shallhave been released.

The shovel revolves about the shaft and is reenforced suitably 'at 21iand 212 by collars welded to the adjacent walls of the shovel. Since theshaft is iixed against rotation, the preferably op positely woundsprings 202 are connected at one end each to the shovel at 212 and atthe opposite end each to the shaft at 214i. The purpose is that thesprings, with whatever initial torsion may be desirable to support partof the weight of the shovel, shall be wound during and bythe upwardmovement of the shovel, be held by a latch such 4as that at the end ofthe check rod, and shall start the shovel on its swinging downwardmovement toward discharge when the latch is released.

The strength and character of spring will depend upon the motionexpected of it. It may be selected so as to give a quick impulse tostart the downward movement but be unwound before the proper dischargeposition is reached so as to tend to support the shovel against movementbeyond proper discharge position, or it may resiliently assist inrevolution of the shovel in the direction for discharge to a distance ofrevolution beyond normal discharge. In either event, at the timereleased, the shovel must be high enough above `the surface upon whichthere is to be discharge to permit the intended extent of swingingmovement.

Either end of the spring obviously can be connected with the shovel andthe other end with the shaft. In the illustration, the outer ends 215 ofthe springs are passed through slots 216 and the inner ends 211 of thesprings are looped at 21d for engagement with pins 219 within the shaft.Y

Any suitable stop mechanism may be` used to limit the extent of movementof the segment gear along the rack and the stoppage is not limited toGeneva gear stoppage of tooth engagement as at 28d between the rack andgear nor engagement between the shovel 281 (Figure '1) and fixedsurfaces 232.

The movement of the segment gear bodily along the length of the rack toproduce rotary motion. of the gear and revolution of the shoveltranslates this bodily gear movement from reciprocating to rotary gearmovement.

The shovel is pressed forward with the normal pressure-advance of thefront crosshead and with the weight of the shovel resting on .thesloping forward face of the front ofthe shovel. When advance of the rackis stopped by stopping move- `ment of the check rod, the furthermovement of the crosshead carries the gear along the rack in the direcion of the length of the stopped rack, rotating the gear and revolvingthe shovel rigid lwith it until the limit of gear travel along the rackis reached.

The shovel may be locked at the lend of its filling revolution tomaintain it inthe farthest position reached, whether this be full orpartial revolution. One form of lock is shown in Figures 10, 11 and 12.

As the shovel turns upwardly through the pile,

the tilting assembly would tilt in eounterclockwise direction (as viewedin Figure if means for restraining tilting be not used.

If free to tilt, the assembly, inthe absence of shovel-supporting shoes,would turn about the tilting axis in counterclockwise direction (asviewed in Figure 5) until the shovel would rest on the floor of thechamber and, during retraction of the shovel to the general position ofFigure 5 '(dot-and-dash lines), would drag upon the oor of the chamberuntil a point is reached where the moment in the rear of the tiltingaxis overbalances the moment of the shovel, load and the parts infront,l at which point the assembly tilts, lifting the shovel from thechamber floor.l

When means is used to maintain the level of the tilting unit, the shovelis maintained in its partially lifted position throughout retraction tothe side guiding and supporting rods which are rigidly connected withit.

y For bulldozlng use whatever shovel be used, the check rod finger islocated in an angular position where it will not meet with any selectorbar and consequently the check rod and the rack continue to move to theend of movement of the front crosshead.

As suggested, that selector will have been chosen which'stops the checkrod and rack Just when the shovel is about to attack the pile ofmaterial to be gathered and loaded; with the result that the gear in thefront crosshead begins to travel along the rack and the teeth of theshovel rigidly attached to the gear begin to '.lvolve forwardly andupwardly at the very beginning of thev approach of the contact of theshovel with the pile.

It will be noted that the identical action of the shovel takes placebeginning when the check rod is stopped, no matter at what position thestoppage of the check rod takes place.

Some of the fundamental advantages of the present invention are that itgathers the coal into a suitable shovel or scoop by direct thrust,concurrently turns the shovel up through the pile of coal so as to fillthe shovel fully and holds the coal securely within the shovel. Becausethe thrust is direct, the mechanism can be kept exany such position asthat seen in Figure 5. When the center of gravity of the tiltingassembly passes to the `rear of the tilting axis, theassembly will turnabout the tilting axisbut merely to the position which would be reachedafter tilting of the form having the pinch blocks.

In operation, when fluid under pressure has been supplied to the plungercylinder and the plunger or thrustor has started forward and has reacheda point at which the torque due to weights of the front parts includingthe crosshead. the shovel, the side guide rods and the check rod whichlie forwardof the tilting axis have overbalanced the torque due toweightsyof the remainder of the parts of the plunger, side tremely lowso as to operate to its best advantage across the breast within achamber formed by removal of the coal from a thin seam.

This greatly cheapens the loading operation. In contrast to this, atpresent the work must be d'one by hand, or rock must be removed inaddition to the coal for the purpose only of giving room for a high andcumbersome machine.

My machine in practice telescopes to a fraction of its total operatinglength, adjusts to start its gathering operation in any positionshovelup through the pile to complete the illlguide rods and check rod as wellas the cylinder behind the tilting axis so that in the absence oflocking against tilting, automatic tilting forwardly and downwardly hasytaken place. Since the shovel is emptied and in vposition to begingathering. the shovel has settled down upon the longer radius of itsrunners with its teeth in position to engage the pile to be gathered.

Remembering that the side supporting and guiding rods and the plunger(thrustor) are connected to the front crosshead, that the gear rigidwith the shovel is held against rotation by the friction against thelower part of the shovel and that the rigidity of the position of thegear likewise fixes the position of the rack with respect to the otherrods, it is clear that the check rod, as well as the other rods named,will travel forward with the shovel and at the same speed as thecrosshead. This condition of relative speedand maintenance of initialpositions of the rods with respect to the others continues until thecheck rod iinger meets and is stopped by that selector bar whose stoppedposition corresponds with the location of the pile to be handled.

When the check rod nger engages a selector, the check rod is stopped andcorrespondingly the rack upon the endof the check r'od is stopped; butthe plunger (thrustor) continues to move and carry with it the frontcrosshead along with ing of the shovel.

In view of my invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of myinvention without copying the structure shown, and I therefore, claimall such insofar asl they fall within the reasonable spirit and scope ofmy claims.

Having thus described my invention, what `I claim as new and desire tosecure by Letters Patent is:

1'. In a loader, a crosshead, a thrustor connected with the crosshead,side guides for the thrustor connected with the crosshead, a check rod,a rack on the check rod, a loading'tool, a gear attached to the tool andengaging the rack, a xed shaft supporting the gear to swing the tool,and torsion springs about 'the shaft connected respectively with thetool and shaft, whereby as the tool is lifted the springs are wound.

\2. In a loader, a crosshead, a thrustor connected with the crosshead,side guides for the thrustor connected with the crosshead, a check rod,a rack on the check rod, a loading tool, a

the tool is lifted the springs are wound, and latch 15 means by whichthe tool may be held in lifted position.

3. A shovel having a front receiving space between the sides of theshovel and rear boots at the sides and extending rearwardly with respectto the front, a gear for the shovel and a shaft for the gear extendingcrosswise of the shovel through the boots. i

4. A shovel'having a lfront receiving space between the sides of theshovel and rear boots at the sides and extending rearwardly with respectto the front, a shaft extending crosswise of the shovel, a crossheadproviding Journal mounting for the shaft, and spiral springs connectedwith the shaft and with the shovel, whereby upward movement of theshovel will cause tightening of the springs.

5. In a loader, a crosshead,'means for supporting the crosshead, athrustor for projecting the crosshead forward and retracting the same, agear, a shaft rotatably supporting the gear on the crosshead, a loadingtool pivoting on the shaft having a reentrant rear portion and havingboots on either side of the reentrant rear portion and a rackcooperating with the gear.

6. In a loader, a crosshead, means for supporting the crosshead, athrustor for projecting the crosshead forward and retracting the same, a

gear. a shaft rotatably supporting the gear on the" "shaft having areentrant rear portion and having boots on either side of the reentrantrear portion, a rack cooperating with the gear, a check rod connectedwith the rack, and a check for selectively limiting the range ofmovement of the check rod.

8. In a loader, a crosshead, means for supporting the crosshead, athrustor for projecting the crosshead forward and retracting the same, a

gear, a shaft rotatably supporting the gear on the crosshead, a loadingtool pivoting on the shaft having a reentrant rear portion and havingvboots on either side of the reentrant rear portion, a rack cooperatingwith the gear, a check rod connected to the rack, and latch mechanismfor securing the check rod against forward movement with respect to thethrustor.

9. In a loader, a crosshead, means for supporting the crosshead, athrustor for projecting the crosshead forward and retracting the same, agear, a shaft rotatably supporting the gear on the crosshead, a loadingtool pivoting on the shaft having a reentrant rear portion and havingboots on either side of the reentrant rear portion, a rack cooperatingwith the gear, a check rod connected to the rack having latch engagingindentations, a latch having a position selectively engaging in one ofthe indentations for securing the check4 rod against forward movementwith respect to the forward movement with the thrustor, andelectromagnetic mechanism for operating the latch.

10. In a loader, a crosshead, means for supporting the crosshead, athrustor for projecting the crosshead forward and retracting the same, agear, a shaft rotatably supporting the gear on the crosshead, a loadingtool pivoted on the shaft having a reentrant rear portion and havingboots on either side of the reentrant rear portion, a rack cooperatingwith the gear, a check rod connected with the rack, a check for thecheck rod, and latch mechanism for latching the check rod againstmovement forward with respect to the thrustor.

11. In a loader, a crosshead, means for supporting the crosshead, athrustor for projecting the crosshead, forward and retracting the same,a gear, a shaft rotatably supporting the gear on the crosshead, aloading tool pivoted on the shaft having a, reentrant rear portion andhaving boots on either side of the reentrant rear portion, a rackcooperating with the gear, a check rod connected with the rack andyspiral springs interposed hetween the shaft and the loading tool.

12. lin a loader, a shovel having a reentrant rear opening when inloaded position and boots on either side of the reentrant rear, pivotmeans for pivoting the shovel located in the reentrant portion andmechanism for supporting the pivot means, for projecting the sameforward and retracting, and for turning the shovel about the pivot meansto raise the shovel to loaded position, the shovel when moving forwardhaving the boots extending above, the pivot means and the shovelextending downwardly farther than when the shovel is loaded and theboots extend behind the pivot means, the extra vertical height in loadedposition being available for manipulation during retraction.

13. In a loader, a, thrustor, a crosshead mounted on the end of thethrustor, a pivot mounted on the crosshead, a shovel having an open facefor loading, a reentrant rear portion,

Vlooots on either side thereof and a forward blade,

pivotally supported with the shovel pivot in the reentrant portion, theshovel having a length from its forward blade to the back of the bootswhich is substantially greater than the height, and means for turningthe shovel about the pivot, whereby when the shovel is positioned withthe blade down, the open face forward and the boots up it will have amaximum height and maximum open surface for loading, and when the shovelis turned to place the blade forward vand the boots rearward it willhave less height and extra vertical space for manipulation duringretraction.

14. A loader shovel having a reentrant rear portion, a shaft pivotallysupporting the loader shovel, passing across the reentrant rear portionand giving a range of swinging movement of the shovel from emptyingposition to gathering and loading position, in which the containerportion of the shovel lies in part behind the shaft.

JOHN B. MCDADE.

REFERENUES CHTIEID The following references are of record in the ille ofthis patent:

